Intercellular Arc signaling regulates vasodilation

ABSTRACTInjury responses require communication between different cell types in the skin. Sensory neurons contribute to inflammation and can secrete signaling molecules that affect non-neuronal cells. Despite the pervasive role of translational regulation in nociception, the contribution of activity-dependent protein synthesis to inflammation is not well understood. To address this problem, we examined the landscape of nascent translation in DRG neurons treated with inflammatory mediators using ribosome profiling. We identified the activity-dependent gene, Arc, as a target of privileged translation in vitro and in vivo. Inflammatory cues promote local translation of Arc in the skin. Arc deficient mice display exaggerated paw temperatures and vasodilation in response to an inflammatory challenge. Since Arc has recently been shown to be released from neurons in extracellular vesicles, we hypothesized that intercellular Arc signaling regulates the inflammatory response in skin. We found that the excessive thermal responses and vasodilation observed in Arc defective mice are rescued by injection of Arc-containing extracellular vesicles into the skin. Our findings suggest that activity-dependent production of Arc in afferent fibers regulates neurogenic inflammation through intercellular signaling.HIGHLIGHTSRibosome profiling identifies Arc as a target of activity-dependent translationArc is present in the DRG, spinal cord, and skinInduced Arc biosynthesis in skin requires the presence of afferent fibersArc-deficient mice have exaggerated inflammation that is rescued by Arc-containing extracellular vesicles

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Postprandial transfer of colostral extracellular vesicles and their protein and miRNA cargo in neonatal calves

10.21203/rs.2.10032/v1 ◽

2019 ◽

Author(s):

Benedikt Kirchner ◽

Dominik Buschmann ◽

Vijay Paul ◽

Michael W. Pfaffl

Keyword(s):

Extracellular Vesicles ◽

Expression Profiles ◽

Bovine Milk ◽

Cell Types ◽

Specific Protein ◽

In Vivo Experiments ◽

Neonatal Calves ◽

Almost All

Abstract Background Extracellular vesicles (EVs) such as exosomes are key regulators of intercellular communication that can be found in almost all bio fluids. Although studies in the last decade have made great headway in discerning the role of EVs in many physiological and pathophysiological processes, the bioavailability and impact of dietary EVs and their cargo still remain to be elucidated. Due to its widespread consumption and high content of EV-associated microRNAs and proteins, a major focus in this field has been set on EVs in bovine milk and colostrum. Despite promising in vitro studies in recent years that show high resiliency of milk EVs to degradation and uptake of milk EV cargo in a variety of intestinal and blood cell types, in vivo experiments continue to be inconclusive and sometimes outright contradictive. Results To resolve this discrepancy, we assessed the potential postprandial transfer of colostral EVs to the circulation of newborn calves by analysing colostrum-specific protein and miRNAs, including specific isoforms (isomiRs) in cells, EV isolations and unfractionated samples from blood and colostrum. Our findings reveal distinct populations of EVs in colostrum and blood from cows that can be clearly separated by density, particle concentration and protein content (BTN1A1, MFGE8). Postprandial blood samples of calves show a time-dependent increase in EVs that share morphological and protein characteristics of colostral EVs. Analysis of miRNA expression profiles by Next-Generation Sequencing gave a different picture however. Although significant postprandial expression changes could only be detected for calf EV samples, expression profiles show very limited overlap with highly expressed miRNAs in colostral EVs or colostrum in general. Conclusions Taken together our results indicate a selective uptake of membrane-associated protein cargo but not luminal miRNAs from colostral EVs into the circulation of neonatal calves.

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Abstract 376: Downregulation of Endogenous Apelinergic Axis Mediates Endothelial and Organismal Senescence

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.36.suppl_1.376 ◽

2016 ◽

Vol 36 (suppl_1) ◽

Author(s):

Rahul Rai ◽

Asish K Ghosh ◽

Layton H Smith ◽

Douglas E Vaughan

Keyword(s):

Endothelial Cells ◽

Replicative Senescence ◽

Cell Types ◽

Ang Ii ◽

Systematic Assessment ◽

Multiple Cell ◽

Deficient Mice

Background: Apelinergic signaling is a recently discovered GPCR mediated pathway. Endothelial cells are the main source of endogenous apelin (apln) while apelin receptor (aplnr) is present on multiple cell types. Since the role of endogenous apelinergic pathway within the context of senescence is largely unknown, we ask if levels of apln- aplnr vary with aging. We also investigate the effects of downregulated apln- aplnr on cellular and organismal aging. Approach and Results: To assess variations in endogenous apln- aplnr with aging, we compared their levels in 1 month (young) and 1 year old (old) WT mice. We noticed significant downregulation of apln- aplnr with chronological senescence in multiple tissues. Expression of apelin was also reduced with replicative senescence of endothelial cells. L-NAME administration, a model of stress induced senescence, also repressed aortic and cardiac apln. To address the mechanism involved in downregulation of apln- aplnr, we administered young wild type mice with Ang II. After a week of Ang II, there was significant downregulation of aortic apln and aplnr. Ang II and TGF-β also repressed apln and aplnr in vitro . Next we investigated the effects of downregulated apln on endothelial cells. In response to shRNA mediated apelin knockdown, cells exhibited slower proliferation and upregulated senescence associated markers. We observed similar results when endothelial aplnr was blocked with an antagonist, ML221. In addition, apln and aplnr deficient mice also exhibited features of cardiovascular aging, including ventricular hypertrophy and lower EF. Importantly, aplnr deficient mice at eight months of age were also hypertensive. Conclusion: We provide a systematic assessment of senescence associated variation in levels of apln- aplnr. We demonstrate the role of Ang II- TGF-β axis in downregulating apln- aplnr during chronological and stress induced senescence in vivo and in vitro . We propose a novel model of Ang II- TGF-β induced senescence. Where in, with aging Ang II and TGF-β repress endogenous apln- aplnr. Downregulation of endogenous apln- aplnr axis decreases beneficial “youthful” effects of apelin, resulting in endothelial dysfunction and accelerated organismal aging.

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Siliplant1 (Slp1) protein precipitates silica in sorghum silica cells

10.1101/518332 ◽

2019 ◽

Cited By ~ 4

Author(s):

Santosh Kumar ◽

Nurit Adiram-Filiba ◽

Shula Blum ◽

Javier Arturo Sanchez-Lopez ◽

Oren Tzfadia ◽

...

Keyword(s):

Silicic Acid ◽

Cell Types ◽

List Type ◽

Uncharacterized Protein ◽

Silica Precipitation ◽

Precipitated Silica ◽

Immature Leaf ◽

Leaf Epidermal Cell

SummarySilicon is absorbed by plant roots as silicic acid. The acid moves with the transpiration stream to the shoot, and mineralizes as silica. In grasses, leaf epidermal cells called silica cells deposit silica in most of their volume by unknown mechanism.Using bioinformatics tools, we identified a previously uncharacterized protein in sorghum (Sorghum bicolor), which we named Siliplant1 (Slp1). Silica precipitation activity in vitro, expression profile, and activity in precipitating biosilica in vivo were characterized.Slp1 is a basic protein with seven repeat units rich in proline, lysine, and glutamic acid. A short peptide, repeating five times in the protein precipitated silica in vitro at a biologically relevant silicic acid concentration. Raman and NMR spectroscopies showed that the peptide attached the silica through lysine amine groups, forming a mineral-peptide open structure. We found Slp1 expression in immature leaf and inflorescence tissues. In the immature leaf active silicification zone, Slp1 was localized to the cytoplasm or near cell boundaries of silica cells. It was packed in vesicles and secreted to the paramural space. Transient overexpression of Slp1 in sorghum resulted in ectopic silica deposition in all leaf epidermal cell types.Our results show that Slp1 precipitates silica in sorghum silica cells.

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Atg5-Deficient Mice Infected with Francisella tularensis LVS Demonstrate Increased Survival and Less Severe Pathology in Internal Organs

Microorganisms ◽

10.3390/microorganisms8101531 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1531

Author(s):

Ina Kelava ◽

Mirna Mihelčić ◽

Mateja Ožanič ◽

Valentina Marečić ◽

Maša Knežević ◽

...

Keyword(s):

Francisella Tularensis ◽

Cell Types ◽

Internal Organs ◽

Tularensis Subsp ◽

Cell Cytosol ◽

Severe Pathology ◽

Deficient Mice

Francisella tularensis is a highly virulent intracellular pathogen that proliferates within various cell types and can infect a multitude of animal species. Francisella escapes the phagosome rapidly after infection and reaches the host cell cytosol where bacteria undergo extensive replication. Once cytosolic, Francisella becomes a target of an autophagy-mediated process. The mechanisms by which autophagy plays a role in replication of this cytosolic pathogen have not been fully elucidated. In vitro, F. tularensis avoids degradation via autophagy and the autophagy process provides nutrients that support its intracellular replication, but the role of autophagy in vivo is unknown. Here, we investigated the role of autophagy in the pathogenesis of tularemia by using transgenic mice deficient in Atg5 in the myeloid lineage. The infection of Atg5-deficient mice with Francisella tularensis subsp. holarctica live vaccine strain (LVS) resulted in increased survival, significantly reduced bacterial burden in the mouse organs, and less severe histopathological changes in the spleen, liver and lung tissues. The data highlight the contribution of Atg5 in the pathogenesis of tularemia in vivo.

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Extracellular Vesicles in Organ Fibrosis: Mechanisms, Therapies, and Diagnostics

Cells ◽

10.3390/cells10071596 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1596

Author(s):

David R. Brigstock

Keyword(s):

Extracellular Vesicles ◽

Cell Types ◽

Chronic Injury ◽

Increased Risk ◽

End Stage ◽

Parenchymal Cells ◽

Risk Of Cancer ◽

Organ Fibrosis

Fibrosis is the unrelenting deposition of excessively large amounts of insoluble interstitial collagen due to profound matrigenic activities of wound-associated myofibroblasts during chronic injury in diverse tissues and organs. It is a highly debilitating pathology that affects millions of people globally and leads to decreased function of vital organs and increased risk of cancer and end-stage organ disease. Extracellular vesicles (EVs) produced within the chronic wound environment have emerged as important vehicles for conveying pro-fibrotic signals between many of the cell types involved in driving the fibrotic response. On the other hand, EVs from sources such as stem cells, uninjured parenchymal cells, and circulation have in vitro and in vivo anti-fibrotic activities that have provided novel and much-needed therapeutic options. Finally, EVs in body fluids of fibrotic individuals contain cargo components that may have utility as fibrosis biomarkers, which could circumvent current obstacles to fibrosis measurement in the clinic, allowing fibrosis stage, progression, or regression to be determined in a manner that is accurate, safe, minimally-invasive, and conducive to repetitive testing. This review highlights the rapid and recent progress in our understanding of EV-mediated fibrotic pathogenesis, anti-fibrotic therapy, and fibrosis staging in the lung, kidney, heart, liver, pancreas, and skin.

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Biodistribution, Uptake and Effects Caused by Cancer-Derived Extracellular Vesicles

Journal of Circulating Biomarkers ◽

10.33393/jcb.2015.2052 ◽

2015 ◽

Vol 4 (1) ◽

Author(s):

Lilite Sadovska ◽

Cristina Bajo Santos ◽

Zane Kalniņa ◽

Aija Linē

Keyword(s):

Extracellular Vesicles ◽

Cell Types ◽

Cell Phenotype ◽

Chromosomal Dna ◽

Metastatic Niche ◽

Paracrine Signalling ◽

Cancerous Cell ◽

The Impact

Extracellular vesicles (EVs) have recently emerged as important mediators of intercellular communication. They are released in the extracellular space by a variety of normal and cancerous cell types and have been found in all human body fluids. Cancer-derived EVs have been shown to carry lipids, proteins, mRNAs, non-coding and structural RNAs and even extra-chromosomal DNA, which can be taken up by recipient cells and trigger diverse physiological and pathological responses. An increasing body of evidence suggests that cancer-derived EVs mediate paracrine signalling between cancer cells. This leads to the increased invasiveness, proliferation rate and chemoresistance, as well as the acquisition of the cancer stem cell phenotype. This stimulates angiogenesis and the reprogramming of normal stromal cells into cancer-promoting cell types. Furthermore, cancer-derived EVs contribute to the formation of the pre-metastatic niche and modulation of anti-tumour immune response. However, as most of these data are obtained by in vitro studies, it is not entirely clear which of these effects are recapitulated in vivo. In the current review, we summarize studies that assess the tissue distribution, trafficking, clearance and uptake of cancer-derived EVs in vivo and discuss the impact they have, both locally and systemically.

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Efficient in vivo genome editing mediated by stem cells-derived extracellular vesicles carrying designer nucleases

10.1101/2021.02.25.432823 ◽

2021 ◽

Author(s):

Sylwia Bobis-Wozowicz ◽

Karolina Kania ◽

Kinga Nit ◽

Natalia Blazowska ◽

Katarzyna Kmiotek-Wasylewska ◽

...

Keyword(s):

Stem Cells ◽

Genome Editing ◽

Extracellular Vesicles ◽

Gene Knockout ◽

Marker Gene ◽

Cell Types ◽

Zinc Finger Nucleases ◽

Transcription Activator

Precise genome editing using designer nucleases (DNs), such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) system, has become a method of choice in a variety of biological and biomedical applications in recent years. Notably, efficacy of these systems is currently under scrutiny in about 50 clinical trials. Although high DNs activity in various cell types in vitro has already been achieved, efficient in vivo genome editing remains a challenge. To solve this problem, we employed stem cells-derived extracellular vesicles (EVs) as carriers of DNs. We used umbilical cord-derived mesenchymal stem cells (UC-MSCs) and induced pluripotent stem cells (iPSCs) as EV-producer cells, since they are both applied in regenerative medicine. In our proof-of-concept studies, we achieved up to 50% of EGFP marker gene knockout in vivo using EVs carrying either ZFN, TALEN or the CRISPR/Cas9 system, particularly in the liver. Importantly, we obtained almost 50% of modified alleles in the liver of the experimental animals, when targeting the Pcsk9 gene, whose overexpression is implicated in hypercholesterolemia. Taken together, our data provide strong evidence that stem cells-derived EVs constitute a robust tool in delivering DNs in vivo, which may be harnessed to clinical practice in the future.

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Ultrastructural observations on the in vitro cytoadherence of Plasmodium falciparum infected red blood cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100162132 ◽

1990 ◽

Vol 48 (3) ◽

pp. 914-915

Author(s):

D.J.P. Ferguson ◽

A.R. Berendt ◽

J. Tansey ◽

K. Marsh ◽

C.I. Newbold

Keyword(s):

Plasmodium Falciparum ◽

Red Blood Cells ◽

Blood Cells ◽

Umbilical Vein ◽

Cell Types ◽

Amelanotic Melanoma ◽

Cytoplasmic Process ◽

Umbilical Vein Endothelial Cells

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).

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LACK OF EFFECT OF CORTICOSTEROIDS ON THE IN VIVO DISAPPEARANCE OF SULFHYDRYL-INHIBITED AND ANTIBODY-COATED ERYTHROCYTES

Acta Endocrinologica ◽

10.1530/acta.0.047s028 ◽

1964 ◽

Vol 47 (3_Suppl) ◽

pp. S28-S36

Author(s):

Kailash N. Agarwal

Keyword(s):

Red Cells ◽

List Type ◽

Red Cell

ABSTRACT Red cells were incubated in vitro with sulfhydryl inhibitors and Rhantibody with and without prior incubation with prednisolone-hemisuccinate. These erythrocytes were labelled with Cr51 and P32 and their disappearance in vivo after autotransfusion was measured. Prior incubation with prednisolone-hemisuccinate had no effect on the rate of red cell disappearance. The disappearance of the cells was shown to take place without appreciable intravascular destruction.

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